package wh.jf.singleton;

/**
 * 懒加载 多线程安全
 */
public class Singleton4 {
    private static class Singleton4Holder {
      private static final Singleton4 INSTANCE = new Singleton4();
    }
    private Singleton4 (){}
    public static final Singleton4 getInstance () {
      return Singleton4Holder.INSTANCE;
    }
}
